


Heat

by Kittychatuwu



Category: Miraculous Ladybug
Genre: Adrien Agreste Needs Love, Adrien Agreste | Chat Noir Needs a Hug, Adrien Agreste/Marinette Dupain-Cheng Fluff, Consensual Underage Sex, Eventual Smut, F/M, Implied/Referenced Sex, Implied/Referenced Underage Sex, Mating Cycles/In Heat, Mildly Dubious Consent, Minor Plagg/Tikki, Miraculous Side Effects, Plagg is a Little Shit (Miraculous Ladybug), Poor Adrien Agreste | Chat Noir, Poor Tikki (Miraculous Ladybug), Smut
Language: English
Status: Completed
Published: 2020-11-04
Updated: 2020-11-04
Packaged: 2021-03-09 03:29:01
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,782
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27387976
Author URL: https://archiveofourown.org/users/Kittychatuwu/pseuds/Kittychatuwu
Summary: Plagg had explained later on through fits of laughter (while Tikki scolded him for not explaining this side effect to the boy sooner) that Adrien was indeed experiencing his heat cycle much like a cat would. He got them monthly from there, and Marinette began to notice the signs pretty quickly.Or, Adrien goes into heat and breaks their golden rule.
Relationships: Adrien Agreste | Chat Noir/Marinette Dupain-Cheng | Ladybug
Comments: 9
Kudos: 267





	Heat

**Author's Note:**

> Idk what this is lmaoo  
> Also my first attempt at posting to AO3!  
> I just love the idea of the side effects of the miraculous charms, and I couldn't quite get this one out of my head.
> 
> Rated explicit to be safe, but there isn't anything particularly graphic, mostly just implied

The first time Adrien had went into heat a year ago, it was confusing for both of them.

He had been extra clingy to her that day to the point even their friends noticed, and during patrol he almost fell to his death a dozen times because he was too busy staring at her.

They had been 16, and dating for only two weeks, and had yet to do anything above PG.

Typically Adrien was the perfect gentleman, but when they were kissing that night on the rooftop he was so grabby that she ended up tying him to the chimney with her yoyo.

Plagg had explained later on through fits of laughter (while Tikki scolded him for not explaining this side effect to the boy sooner) that Adrien was indeed experiencing his heat cycle much like a cat would.  
He got them monthly from there, and Marinette began to notice the signs pretty quickly.

The flushed cheeks and lack of appetite usually came first, and then Adrien craved physical comfort and a nest of sorts.

Then his desire for physical contact became a bit less innocent, and he began to struggle to control himself.  
Luckily now, after over a year of dating, they were no longer virgins and the type of intimacy he craved, Marinette could deliver.

That seemed to make the heats a lot easier and helped them pass quicker, too.

She remembered spending days, sometimes a full week, with Adrien couped up in her room refusing to leave the pile of her clothes he had set up as a nest for himself as he sobbed and begged to be touched.  
He always said beforehand not to give in, and for the longest time Marinette obeyed, but she worried about him. While in heat he would eat very little and burn up badly. All she could seem to do was cuddle him and try to keep the fever down whilst making futile attempts get something into his stomach.

His first heat cycle after they had sex was much easier.

He was only in heat for 24 hours, and she couldn't say she minded all the sex.

Since then it seemed his heats had levelled out a bit, lasting between two days to sometimes three if Marinette was too busy to give him her full attention, although she always tried her best to because she knew Adrien despised being in heat. He hated the pains as well as the lack of control he seemed to have, and would often label it as taking advantage of her even though she reassured him a billion times he wasn't. 

They had a rule that if he could sense his heat coming on, he wouldn't come to school.

He would head straight to her balcony and go through the skylight, and try to settle himself there and wait for her if she wasn't home. It was too obvious at school, and he was in no state to go.

That was why she was pretty damn mad when she saw Adrien and Nino walking towards her and Alya, with Adriens cheeks that usual flushed red colour.

"Hey guys" Alya greeted, kissing Nino on the cheek and taking his hand.

Adrien kissed her hard on the lips, and instead of just taking her hand like normal he wrapped his arms around her arm and clung, his head falling on her shoulder.

That confirms her suspicions, then.

Alya gave them a curious look and Marinette just shrugged with what she hoped was a convincing smile. Their friends walked ahead and Marinette fell a few steps behind, practically dragging Adrien up the steps.  
"You should've went to mine, kitty" she hissed quietly and he looked up, loosening his grip with his eyes wide and sad.  
She forgot that heat seemed to turn all his emotions to 100.  
"I- I'm older now. I can handle it" he said, untangling himself from her and staring downwards as he shuffled his feet.  
"Adrien..."  
"No, I'm fine. I can handle it and I'll prove it" he huffed, walking off in the direction of class even if they still had 20 minutes to kill.  
This was going to end very badly. 

By lunch, she knew her earlier worry was right.  
Adrien had been quiet and distant all day, and Nino had asked him if he was ok multiple times.

He had said yes, but she knew he was lying.

He was squirming incessantly in his chair, and he had long since shrugged off his white jacket as his body temperature got higher.

He stared at his lunch in distain.  
He shuffled in his seat. Bit his lip.  
Itched at his arms and neck as he felt every nerve in his body beg for human contact.

"You eating that, dude?" Nino asked, nudging his friends arm and Adrien fucking purred, leaning into the minuscule touch like a lifeline and rested his head against his best friends arm.

Nino sat frozen, and the expression on his face would've been comedic gold if the situation wasn't so bad.

Alya was gaping too, staring at her friend, unsure what to say about his sudden affection.  
To Ninos credit, he did lift an arm to wrap around his bros shoulders, but Marinette knew it would only make Adrien lose control of himself more.

"Adrien isn't feeling too well today, I think it's time I take him home" Marinette smiled, getting up and yanking her boyfriend up using his sleeve.  
"Oh, ok. That explains his clinginess then" Alya teased, but Adrien wasn't paying attention, too busy wrapping his arms around her waist and sneaking a touch to her...

She grabbed his wrist and pulled him off, linking their hands to subdue him a tiny bit.  
"Yeah" she forced a small laugh.

"I'll make notes for you guys, hope you're feeling better tomorrow dude" Nino said, and this time Adrien managed a nod before Marinette pulled him out the lunch hall and out of the school.

"Mari..." he groaned but she pointedly ignored him until she got them behind the school and into an alleyway.

Immediately Adrien pinned her against the wall and began going to work on her neck, but she shoved him off.

Plagg emerged from his bag laughing as she watched the blonde pout, and Tikki flew out of hers to bash the black cat over the head.  
"You should've listened to me, Adrien! We have the no school rule for a goddamn reason!" She seethed and he wrapped his arms around himself.  
"I just thought-"  
"No! You didn't think, and that's the problem! You can't control yourself, and the last place you should be is in school! You just spent the day embarrassing me and weirding people out, and I-" she hadn't really been watching him during her rant, but his quiet sob pulled her out of it.

"He didn't mean to, Marinette. He just didn't want to let his heats inconvenience you, wanted to see if he could push through them" Plagg admitted on behalf of his chosen, who was crying miserably into his hands.

He was doing it for her. He didn't want her to have to look after him all the time.

She felt awful, sighing softly as she stepped forward and engulfed him in a hug.  
"Shhh, it's ok. I'm sorry, Chaton. I was just worried about you all day, it's important you get rest during your heats" she soothed, letting him cling to her like a lifeline as he cried and tried to breath in her scent.

"I'm so sorry, Adrien. Let's get you back to mine, ok?" She suggested but he tensed up, gripping onto her to the point it was almost painful.  
"W-will you s-stay? I need you, Mari" he whimpered and she nodded quickly.  
"Of course, I'm not leaving you for the rest of the day. Tikki, spots on" she called, and the kwami gladly flew into her earrings and transformed her.

Transforming to Chat usually worsened Adriens heats, exhuberating the symptoms even further, and so they avoided that transformation as much as possible.  
"Ok, get into Adriens bag" she told Plagg and the kitty obeyed.

Marinette smiled and passed him a piece of cheese she kept in her own bag, knowing full well that the kwami would not be impressed about missing lunch (she saw Adrien sneaking pieces of his lunch into his bag every day, even if her boyfriend continued to deny the fact).

"Cmon, sweetheart" she murmured, scooping him up with ease.  
He linked his arms around her neck and buried his nose between her chest, making her flush slightly.  
She used her yoyo to fly up onto the rooftops, and headed back to her home.

"It's ok, shh, settle down" she directed gently, maneuvering him into the nest she had quickly thrown together with her clothes and a few blankets, sprayed with some of her perfume too.  
Ordinarily Adrien preferred making his own, but he wouldn't let go of her long enough to do so.  
"We need to get his temperature down" Plagg noted worriedly, feeling the boys head with concern.

Adrien hissed, actually hissed at the kwami and strengthened his hold on her defensively.

Plagg scoffed, fixing him with a glare.  
"Did you just hiss at me, kid? Because I swear-"  
"Plagg, you know he can't help it. Heat makes you territorial too" Tikki pointed out and the demi gods cheeks heated slightly and he huffed.  
"Does not!"

Marinette decided to let them bicker, her hand gently stroking through Adriens hair as he began trying to kiss at her neck, clawing at her shirt.  
"Bad kitty! Adrien, you need to listen to me. Lie in your nest while I go and get some stuff to get your temperature down" she ordered, but he just shook his head.  
"Fine. Tikki, spots on!"

She sighed and pulled out her yoyo, using her super strength to pin him into the nest and tie him up.  
His eyes welled with tears and she tried to avoid looking at him in fear her resolve would crumble immediately.

"He's been away from you all day, his cravings are stronger but he will be fine" Plagg spoke, and she nodded, standing up only for Adrien to completely fall apart at her feet.

"Mari! Marinette please y-you said you would stay! Please!" He was back to sobbing, twisting his body in the rope trying to reach for her.

She winced, kneeling down in front of him and stroking his hair.

"Adrien. Stop. Look at me" she said firmly and this time he seemed to actually listen, staring up at her.  
"I'm just going downstairs. Plagg will stay with you. Count to 60 and I promise I'll be back by then" she said and he whimpered in response.  
"Be a good boy for me, please. I need to help you Chaton" finally he gave a tiny nod and she kissed him before getting up and racing downstairs to collect the supplies. 

30 minutes later she was sat on her bed, with Adrien subdued for now in her lap, nuzzling into her neck as she cuddled him close.  
Tikki took the thermometer from under his arm and smiled.  
"Its going down, the fevers broken" she announced happily, and everyone in the room seemed to breath a collective sigh of relief.

He would be ok.

Adriens nuzzling turned to soft kisses, light bites that made her gasp.  
"C-can we... now?" He mumbled hotly against her skin, clearly getting a little impatient.

She had been able to feel his hard length pressed against her stomach for the past 20 minutes.  
Marinette knew if it was down to him they would've screwed in the alleyway three quarters of an hour ago, and she has to admit that he has been incredibly patient as he allowed her to curve his temperature first and foremost.

"Of course. Tikki, Plagg, I left some snacks on the balcony for you both" she said and Tikki gave her a knowing grin, pulling her other half out the room as he whined about being demoted outdoors like a common housecat, for sex of all things.

The second they were gone Adriens movements began to get a bit more desperate and hungry, kissing and sucking on her neck in a way she knew was going to leave marks.  
Ordinarily she may of scolded him, but she couldn't find it in herself to do so right now.

Besides, she knew Adrien would be gushing apologies and buying her the best concealer on the market when he came down from this heat.

His hands began to trail around her body, and she lay back on the pillows and let him explore.  
He pulled her shirt off quickly and began rutting against her, fingers brushing over her nipple as he sucked at the other.  
She writhed and gasped under him, getting lost in the pleasure of it all as her fingers tangled in his hair.  
"We have all night" she reminded, and his hot mouth moved from her chest and travelled downwards again, until he was giving long, hot licks to the front of her jeans.

She quickly undid them and he pulled them off gladly, before yanking her underwear until the lace snapped.  
She huffed, fingers digging into her scalp.  
"Bad kitty" she scolded, but it was hard to sound serious when Adrien began pressing warm open kisses to her thighs, moving upwards. 

~~~~~

Marinette woke a couple of days later with a yawn, stretching her limbs as the sun began to shine in the room.  
Luckily, Chats heat had lined up with the weekend and so they were able to spend yesterday in bed most of the day.

She scrunched her nose as she felt the come from last nights final session dried on her stomach.  
She supposed she had been too tired to get up and clean herself down.

She found herself wondering if Adrien was out of it yet, and just as she did her boyfriend stirred next to her where he had been tucked against her side tightly.  
His eyes fluttered open, and they were no longer glazed and clouded with that familiar lust.

She was quite relieved in all honesty.

She loved sex with Adrien, but her body could only handle so much and she wasn't sure she could've managed a fourth day of his constant libido.

"Marinette?" He whispered, slowly untangling himself from her.  
"Morning" she smiled, kissing his cheek sweetly.  
Adrien blinked once, then twice as he glanced around the room.

She knew going into heat was quite distorientating for him sometimes.

His mind was so desperate for contact that it sort of shut everything else out, and after he came down his memory could be a little fuzzy.

"I..." he paused, staring at the ceiling with his brows furrowed, and she noticed the tears before they even fell.

"I went to school! I-I broke the rule and I was awful! I'm so sorry Mari, oh my God you must be furious at me" he cried, hiding his face in his hands and rolling away so he wasn't facing her.

"Adrien-" she tried, sitting up and pulling her shirt over her head.  
"I- I was acting like a complete idiot grabbing onto you like that! I could've hurt you" he wailed and she sighed, grabbing his shoulder to turn him onto his back to look at her.

"Settle down, Chaton. I'm perfectly fine. Going to school wasn't you're wisest choice, but I understand why you did. I'm not angry at you" she said, reaching out to brush his tears away.  
He sat up with a sniffle, still avoiding her gaze.

"I wish you didn't have to deal with this, it's so unfair on you m'lady. I'm useless" he said sadly and her gaze softened as she shuffled closer, wrapping her arms around his waist and resting her head between his shoulder blades.

"Is it unfair on you when I need to curl in your arms to get warm at the slightest chill?" She asked.  
"No! The ladybug miraculous makes your body colder, you can't help it" he answered immediately.  
"Is it unfair on you when you need to go searching for a particular flower type I'm craving?"  
"Of course not! It's-"  
"Exactly, Chaton. My miraculous gives me side effects that you help me with all the time. Without hesitation. I'm never going to get angry at you for needing me, especially when you can't help it" she explained, and he turned around to hug her tightly.

"Thank you, I couldn't ask for a better ladybug" he mumbled into her shoulder.  
"And I couldn't ask for a better kitty" she smiled.


End file.
